392 



DISSECTION OF THE PERINEUM. 



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removing loose fatty tissue, its line of attachment to the bones externally, 

 and to the triangular ligament posteriorly, will be brought into view. 

 The septum along the middle line should be also defined. To demonstrate 

 more completely the attachment of this subcutaneous layer to the pubic 

 arch between the perinatal space and the thigh, it will be necessary to take 

 away from the left limb the fat on the fascia lata, external to the line of 

 the bone. 



In the fat of the thigh on the right side the student should seek the in- 

 ferior pudendal nerve, which pierces the fascia lata one inch anterior to 

 the tuber ischii, and about the same distance from the margin of the pubic 

 arch ; and should trace its junction in the fat with the inferior haemor- 

 rhoidal nerve. Afterwards the nerve is to be followed forwards to where 

 it enters beneath the superficial fascia in the middle line. 



Fig. 130. 



SUPERFICIAL DISSECTION OF THE ANTERIOR HALF OF THE PERINJECM. 



(Illustrations of Dissections.) 

 Muscles : Arteries : 



A. Ejaculator urinae. a. Transverse perinaal. 



B. Erector penis. . b. Superficial perinteal. 

 c. Transversalis perinsei. c. Brauch of sciatic. 



D. Levator ani. Nerves: 



B. Glutens maximus. 1. Inferior haemorrhoidal. 



o. Crus penis. 2 and 3. Superficial perinaeal. 



H. Urethra. 4. Inferior pudendal. 



The subcutaneous fatty layer or the superficial fascia of the anterior 

 half of the perinaeum is continuous with that cf the adjoining regions; 

 and its depth, and the quantity of fat in it, will vary with the condition of 

 the body. It resembles the corresponding stratum of the groin and upper 

 part of the thigh, in consisting of two different portions. 



One, a subcutaneous fatty part, continuous with that of the rest of the 

 body, which loses its fat towards the scrotum, and obtains there involun* 

 tary muscular fibres. 



